645868546 has 4 divisors (see below), whose sum is σ = 968802822. Its totient is φ = 322934272.

The previous prime is 645868493. The next prime is 645868579.

645868546 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 559842921 + 86025625 = 23661^2 + 9275^2 .

It is a junction number, because it is equal to n+sod(n) for n = 645868493 and 645868502.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161467135 + ... + 161467138.

Almost surely, 2^645868546 is an apocalyptic number.

645868546 is a deficient number, since it is larger than the sum of its proper divisors (322934276).

645868546 is a wasteful number, since it uses less digits than its factorization.

645868546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322934275.

The product of its digits is 5529600, while the sum is 52.

The square root of 645868546 is about 25413.9439284815. The cubic root of 645868546 is about 864.3999072147.

The spelling of 645868546 in words is "six hundred forty-five million, eight hundred sixty-eight thousand, five hundred forty-six".